1. Field of the Invention
The present invention relates to a disk player, and a turntable, a clamper and a spindle motor which are adopted for the same and, more particularly, to a disk player having a self-compensating dynamic balancer for restricting internal vibrations generated due to an eccentric center of gravity of a disk, and a turntable incorporating the self-compensating dynamic balancer, a clamper incorporating the self-compensating dynamic balancer and a spindle motor incorporating the self-compensating dynamic balancer which are adopted for the same.
2. Description of the Related Art
In general, a disk player records and/or reads information onto and/or from a recording medium such as a compact disk (CD), a CD-ROM and a digital versatile disk (DVD). Due to its sensitivity, the disk player is required to protect the disk and optical pickup from external impacts and internal vibrations.
A typical disk player, as shown in FIG. 1, includes a deck base 10 hinge-coupled to a housing (not shown) to be capable of rotating vertically, a deck plate 20 coupled to the deck base 10, a spindle motor 21 installed at the deck plate 20 for providing a rotational force to a disk 1, a turntable 23 coupled to a rotational shaft 22 of the spindle motor 21 for accommodating the disk 1, a clamper 40 installed on the inner surface of the upper portion of the housing to face the turntable 23 for securing the disk 1 placed on the turntable 23, and an optical pickup 25 coupled to the deck plate 30 to be capable of moving across the disk 1 for performing recording and reproduction operations. The disk player includes buffering members 30 disposed between the deck base 10 and the deck plate 20 to prevent the external vibrations transferred through the deck base 10 from being transferred directly to the deck plate 20, the spindle motor 21 and the optical pickup 25. The buffering members 30 are formed of a material such as soft rubber or polyurethane which can absorb external impacts.
The disk player adopting the buffering members 30 as above can effectively protect the driving of the disk 1 and the optical pickup 25 from external impacts. However, a method of dampening internal vibrations generated by the rotation of the spindle motor 21 due to an eccentric center of gravity of the disk is not taken into consideration. In such a case, the eccentric center of gravity of the disk is caused by a discrepancy between the rotational center of the disk and the center of gravity of the disk due to errors in the manufacturing process of the disk. Thus, the rotational shaft of the spindle motor 21 exhibits an orbital revolution due to wobbling of the rotational shaft.
Such orbital revolution of the rotational shaft of the spindle motor does not effect a low-speed disk player such as a 1× or 2× type. However, in the case of a high-speed model such as a 6×, 8×, 12×, 20× or 24× type, the effects of the orbital revolution of the rotational shaft of the spindle motor become serious making the recording/reproducing of information difficult.
To overcome the above problems, in a conventional high-speed disk player, the mass of the deck plate where the spindle motor is installed is increased or the rigidity of the buffering members is increased to reduce movements of the deck plate due to the eccentric center of gravity of the disk.
However, not only is the deck plate having increased mass inappropriate for a high speed rotation, but also the costs of the product increase and miniaturization of the product is hindered. Also, when the rigidity of the buffering members is increased, it is not possible to effectively dampen the external impacts or vibrations.